Groundwater Regulation in a Drying South West Michael Bennett and Alex Gardner Faculty of Law, The University of Western Australia 30 June 2014 ISBN: 978-1-74052-306-6 NATIONAL CENTRE FOR GROUNDWATER RESEARCH & TRAINING GPO Box 2100 ADELAIDE SA 5001 Australia p: +61 8 8201 2193 f: +61 8 8201 7906 [email protected] www.groundwater.com.au The National Centre for Groundwater Research and Training is an Australian Government initiative, supported by the Australian Research Council and the National Water Commission. Contents Preface .................................................................................................................................... vi Acknowledgements ................................................................................................................ vii Executive summary ............................................................................................................... viii 1. Groundwater policy and regulation ..................................................................................... 1 1.1 Policy objectives for groundwater management ............................................................ 1 1.2 Legal models for groundwater management ................................................................. 3 1.3 Western Australia’s regulatory framework ..................................................................... 4 1.4 Water law reform in Western Australia ........................................................................ 16 2. Groundwater challenges in a drying South West .............................................................. 18 2.1 Water resources of the South West ............................................................................. 18 2.2 The drying trend and its impacts on water resources .................................................. 20 2.3 Future scenarios for groundwater in the South West .................................................. 29 3. Overview of regulatory issues and reforms ....................................................................... 32 4. Broader regulatory coverage ............................................................................................ 34 4.1 Unlicensed water use in a drying climate .................................................................... 34 4.2 Basic landholder rights - domestic garden bores ......................................................... 35 4.3 Commercial plantations ............................................................................................... 36 5. Better groundwater planning ............................................................................................. 40 5.1 Statutory water plans and sustainable extraction limits ............................................... 40 5.2 A duty to consider and address risks from climate change ......................................... 42 5.3 Sharing groundwater with the environment in a drying climate ................................... 47 5.4 Sharing groundwater between consumptive uses in a drying climate ......................... 51 6. Flexible water entitlements ............................................................................................... 55 6.1 The need for flexibility in a drying climate .................................................................... 55 6.2 Problems with the existing entitlements system .......................................................... 56 6.3 An alternative approach: share-based entitlements .................................................... 62 6.4 Risk assignment and compensation ............................................................................ 67 6.5 Improved water accounting .......................................................................................... 72 7. Greater use of water markets ........................................................................................... 77 7.1 Water markets and climate change adaptation ........................................................... 77 7.2 Allocating groundwater ................................................................................................ 78 7.3 Trading groundwater .................................................................................................... 85 8. Applying the reforms to groundwater resources in the South West ................................. 90 8.1 Defining the consumptive pool in the face of uncertainty ............................................ 90 iii 8.2 Maintaining incentives for groundwater exploration ..................................................... 91 8.3 Providing sufficient reliability for water users ............................................................... 93 8.4 Managing the transition to the new system ................................................................. 94 8.5 Using groundwater as a ‘drought reserve’ ................................................................... 96 9. Conclusion: groundwater regulation in a drying climate ................................................. 101 Appendix A ...................................................................................................................... 103 Appendix B ...................................................................................................................... 108 Appendix C ...................................................................................................................... 109 Appendix D ...................................................................................................................... 110 Appendix E ...................................................................................................................... 111 Appendix F ....................................................................................................................... 113 Appendix G ...................................................................................................................... 115 Appendix H ...................................................................................................................... 116 Appendix I ........................................................................................................................ 118 Appendix J ....................................................................................................................... 119 Appendix K ...................................................................................................................... 121 References .......................................................................................................................... 124 List of figures Figure 1: Water resources of the South West ....................................................................... viii Figure 2: When is a licence required to take groundwater? .................................................. 10 Figure 3: Yarragadee aquifer salinity levels .......................................................................... 18 Figure 4: Rainfall trend in Western Australia (1970-2012,mm/10yrs) ................................... 20 Figure 5: Annual rainfall in SWWA (1900-2013) Figure 6: Winter rainfall in SSWA (1900-2013) ..................................................................... 20 Figure 7: Streamflow to Perth Dams (1911-2011) ................................................................ 22 Figure 8: Water sources for the Integrated Water Supply System (1940-2023) ................... 23 Figure 9: Gnangara Mound (superficial aquifer) depletion (1979-2009) ............................... 26 Figure 10: Yarragadee Aquifer (deeper aquifer) pressure levels (1973-2011) ..................... 26 Figure 11: Water table trend in the southern Perth Basin (1980-2007) ................................ 27 Figure 12: Projected change in groundwater levels in superficial aquifers of the southern Perth Basin between 2008 and 2030 (median future climate) .............................................. 30 Figure 13: Unlicensed use crowds out licenced use in a drying climate ............................... 34 Figure 14: CSIRO scenario for decline in Perth rainfall due to climate change (1987) ......... 43 Figure 15: CSIRO scenario compared to actual rainfall ....................................................... 44 Figure 16: Non-compliant sites on the Gnangara Mound (% of total sites)........................... 49 Figure 17: Recognising over-allocation: adjustment to allocation limits in a drying climate .. 56 Figure 18: Current entitlements vs National Water Initiative entitlements ............................ 63 iv Figure 19: Risk assignment under the National Water Initiative ........................................... 69 Figure 20: An alternative approach to risk assignment ......................................................... 70 Figure 21: Assessment of Expressions of Interest in the Seabird Subarea, Gingin ............. 82 Figure 22: Trade-off between flexibility and reliability in rules for determining consumptive pools ..................................................................................................................................... 93 Figure 23: Variable Groundwater Abstraction Rule (2002-3 to 2007-8) ................................ 97 Figure 24: Variable Groundwater Abstraction Rule (2008-9 to 2011-12) .............................. 98 List of tables Table 1: Examples of provisions in South West groundwater allocation plans ......................